Method for left atrial appendage occlusion

ABSTRACT

Disclosed is an occlusion device for use in a body lumen such as the left atrial appendage. The occlusion device includes an occlusion member and may also include a stabilizing member. The stabilizing member inhibits compression of the left atrial appendage, facilitating tissue in-growth onto the occlusion member. Methods are also disclosed.

This is a continuation of U.S. patent application Ser. No. 10/830,964,filed Apr. 22, 2004, which is a continuation of U.S. patent applicationSer. No. 09/435,562, filed Nov. 8, 1999, now U.S. Pat. No. 7,128,073,which is a continuation-in-part of U.S. application Ser. No. 09/187,200,filed Nov. 6, 1998, now U.S. Pat. No. 6,152,144, the disclosures ofwhich are incorporated in their entireties herein by reference.

BACKGROUND OF THE INVENTION

Embolic stroke is the nation's third leading killer for adults, and is amajor cause of disability. There are over 700,000 strokes per year inthe United States alone. Of these, roughly 100,000 are hemoragic, and600,000 are ischemic (either due to vessel narrowing or to embolism).The most common cause of embolic stroke emanating from the heart isthrombus formation due to atrial fibrillation. Approximately 80,000strokes per year are attributable to atrial fibrillation. Atrialfibrillation is an arrhythmia of the heart that results in a rapid andchaotic heartbeat that produces lower cardiac output and irregular andturbulent blood flow in the vascular system. There are over five millionpeople worldwide with atrial fibrillation, with about four hundredthousand new cases reported each year. Atrial fibrillation is associatedwith a 500 percent greater risk of stroke due to the condition. Apatient with atrial fibrillation typically has a significantly decreasedquality of life due, in part, to the fear of a stroke, and thepharmaceutical regimen necessary to reduce that risk.

For patients who develop atrial thrombus from atrial fibrillation, theclot normally occurs in the left atrial appendage (LAA) of the heart.The LAA is a cavity which looks like a small finger or windsock andwhich is connected to the lateral wall of the left atrium between themitral valve and the root of the left pulmonary vein. The LAA normallycontracts with the rest of the left atrium during a normal heart cycle,thus keeping blood from becoming stagnant therein, but often fails tocontract with any vigor in patients experiencing atrial fibrillation dueto the discoordinate electrical signals associated with AF. As a result,thrombus formation is predisposed to form in the stagnant blood withinthe LAA.

Blackshear and Odell have reported that of the 1288 patients withnon-rheumatic atrial fibrillation involved in their study, 221 (17%) hadthrombus detected in the left atrium of the heart. Blackshear J L, OdellJ A., Appendage Obliteration to Reduce Stroke in Cardiac SurgicalPatients With Atrial Fibrillation. Ann Thorac. Surg., 1996.61(2):755-9.Of the patients with atrial thrombus, 201 (91%) had the atrial thrombuslocated within the left atrial appendage. The foregoing suggests thatthe elimination or containment of thrombus formed within the LAA ofpatients with atrial fibrillation would significantly reduce theincidence of stroke in those patients.

Pharmacological therapies for stroke prevention such as oral or systemicadministration of warfarin or the like have been inadequate due toserious side effects of the medications and lack of patient compliancein taking the medication. Invasive surgical or thorascopic techniqueshave been used to obliterate the LAA, however, many patients are notsuitable candidates for such surgical procedures due to a compromisedcondition or having previously undergone cardiac surgery. In addition,the perceived risks of even a thorascopic surgical procedure oftenoutweigh the potential benefits. See Blackshear and Odell, above. Seealso Lindsay B D., Obliteration of the Left Atrial Appendage: A ConceptWorth Testing, Ann Thorac. Surg., 1996.61(2):515.

Despite the various efforts in the prior art, there remains a need for aminimally invasive method and associated devices for reducing the riskof thrombus formation in the left atrial appendage.

SUMMARY OF THE INVENTION

There is provided in accordance with one aspect of the presentinvention, a method of occluding an atrial appendage. The methodcomprises the steps of inhibiting changes in the volume of theappendage, and occluding the opening to the appendage. The inhibitingchanges in the volume step preferably comprises introducing a bulkingelement into the appendage to resist compression of the appendage wall.Preferably, the bulking element is an expandable element. In oneembodiment, the introducing an expandable bulking element step comprisesdeploying a self-expandable bulking element from a deployment catheter.The occluding step comprises positioning an occlusion element to enclosethe bulking element within the appendage.

In accordance with another aspect of the present invention, there isprovided a method of facilitating cell growth onto an atrial appendageocclusion device. The method comprises the steps of positioning anocclusion device across the opening of the appendage, the occlusiondevice having a tissue attachment surface thereon. The methodadditionally comprises the step of resisting compression of theappendage at least during a tissue attachment period of time. Theresisting step preferably comprises positioning a bulking structurewithin the appendage.

In accordance with a further aspect of the present invention, there isprovided an occlusion device for implantation within the left atrialappendage. The occlusion device comprises an occluding member,enlargeable from a reduced cross section to an enlarged cross section.The occlusion device may further comprise a stabilizing member,enlargeable from a reduced cross section to an enlarged cross section.The enlarged cross section of the stabilizing member may be less thanthe enlarged cross section of the occlusion member. Any of the occludingmember and stabilizing member structures disclosed herein can beprovided as an occluding member alone, without the correspondingstabilizing member.

The occlusion device preferably further comprises a hub between theocclusion member and the stabilizing member. The occlusion membercomprises an expandable frame, which may be made from at least twospokes. Each spoke has a first end and a second end, and the first endis attached to the hub. The spokes are movable between an axialorientation to provide a low profile such as for transluminalimplantation, and a radially enlarged orientation such as duringimplantation within the appendage to occlude the appendage.

The stabilizing member comprises at least two elements which are movablefrom an axial orientation when the stabilizing member is in the reducedcross section to an inclined orientation when the stabilizing member isin the enlarged cross section. In one embodiment, each element comprisesa proximal section, a distal section, and a bend in-between the proximaland distal sections when the stabilizing member is in the enlarged crosssection. Preferably, the occlusion device further comprises at least onetissue attachment element such as a hook, spike or barb.

In accordance with a further aspect of the present invention, there isprovided an occlusion device for occluding a tubular body structure. Theocclusion device comprises a body, having a longitudinal axis. Anexpandable occlusion member is provided at a first position on the axis,and a stabilizing member is provided at a second position on the axis.The occlusion member comprises a plurality of spokes which are hingeablyattached to the body and movable between an axial orientation and aninclined orientation.

Preferably, the occlusion member further comprises a polymeric membranecarried by the spokes. The stabilizing member comprises at least threeradially outwardly movable elements. In one embodiment, a hinge isprovided on the body between the occlusion member and the stabilizingmember. One hinge construction comprises a helical coil.

In accordance with a further aspect of the present invention, there isprovided a method of making an occlusion device. The method comprisesthe steps of providing a tube, having a first end, a second end, and alongitudinal axis. A plurality of axially extending slots are cut at afirst position on the tube, to create a first plurality of longitudinalelements. A second plurality of axially extending slots are cut at asecond position on the tube, to create a second plurality oflongitudinal elements.

The method further comprises the steps of providing a radially outwardlydirected bias on at least one of the first and second plurality ofelements. A polymeric membrane may be attached to at least one of thefirst and second plurality of elements. In one embodiment, a hinge isprovided on the tube in-between the first and second plurality ofelements.

In accordance with a further aspect of the present invention, there isprovided a method of occluding an atrial appendage. The method comprisesthe steps of introducing a stabilizing member into the appendage, forresisting compression of the appendage wall, and preventing rotation andaxial migration of the implant, and positioning an occlusion memberacross the appendage. The introducing step preferably comprisesintroducing a radially expandable stabilizing member, and radiallyexpanding the member within the appendage. The positioning step maycomprise either positioning the occlusion member within the appendage,or positioning the occlusion member across an opening of the appendage.In one embodiment, the introducing and positioning steps areaccomplished by introducing a deployment catheter within the appendageand deploying the stabilizing member and occluding member from thecatheter. Preferably, the method further comprises the step offacilitating cell growth onto the occlusion member.

Further features and advantages of the present invention will becomeapparent to those of ordinary skill in the art in view of the detaileddescription of preferred embodiments which follows, when consideredtogether with the attached drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of an embodiment having features of theinvention with an occluding member and a retention member.

FIG. 2 shows an end view of the apparatus of FIG. 1 in partial section.

FIG. 3 shows a longitudinal cross-sectional view of the apparatus ofFIGS. 1 and 2.

FIG. 3A shows a perspective view of an apparatus having features of theinvention.

FIG. 3B shows an elevational view in partial section of the apparatus ofFIG. 3A.

FIG. 4 shows an elevational view of an apparatus having features of theinvention in a deployed state within a body cavity.

FIG. 5 shows an elevational view of an apparatus having features of theinvention in a deployed state within a body cavity.

FIG. 6 shows a perspective view of an apparatus for sealing off a bodycavity having features of the invention.

FIG. 7 shows an elevational view in partial section of an apparatus forsealing off a body cavity having features of the invention.

FIG. 8 shows a transverse cross-sectional view of the apparatus of FIG.7 taken along lines 8-8.

FIG. 9 shows a schematic view of a patient's heart with a transeptalcatheter deployed through the septum and a delivery catheter andapparatus for sealing off a body cavity disposed therein.

FIG. 10 shows a schematic view of a patient's heart in partial sectionwith a delivery catheter disposed within the opening of the LAA.

FIG. 11 shows a magnified view of the delivery catheter distal end andthe LAA of a patient of FIG. 10 with an apparatus for sealing off a bodycavity partially deployed within the LAA.

FIG. 12 shows the apparatus for sealing off a body cavity of FIG. 11fully deployed within a LAA.

FIG. 13 shows an elevational view of a device for occluding a bodycavity having features of the invention.

FIG. 14 shows a transverse cross sectional view of the device foroccluding a body cavity of FIG. 13 taken along lines 14-14.

FIG. 15 shows a device for occluding a body cavity having features ofthe invention deployed within a LAA.

FIG. 16 shows a device for occluding a body cavity having features ofthe invention deployed within a LAA.

FIG. 17 shows a LAA being occluded by a method having features of theinvention.

FIG. 18 shows a LAA occluded by method having features of the invention.

FIG. 19 shows a LAA occluded by method having features of the invention.

FIG. 20 is an elevational view of an apparatus for closing an interiorbody cavity of a patient in partial section having features of theinvention.

FIG. 21 is a schematic view of an apparatus for closing an interior bodycavity of a patient in contact with tissue of a LAA.

FIG. 22 is a schematic view of an apparatus for closing an interior bodycavity of a patient in contact with tissue of a LAA.

FIG. 23 shows a LAA which has been closed by a method having features ofthe invention.

FIG. 24 is a perspective view of an occlusion device in accordance withthe present invention.

FIG. 25 is a side elevational view of the occlusion device shown in FIG.24.

FIG. 26 is a perspective view of an alternate embodiment of the presentinvention.

FIG. 27 is a side elevational view of the embodiment shown in FIG. 26.

FIG. 28 is a perspective view of a further embodiment of the presentinvention.

FIG. 29 is a side elevational view of the embodiment of FIG. 28.

FIG. 30 is a perspective view of a further occlusion device inaccordance with the present invention.

FIG. 31 is an end view taken along the line 31-31 of FIG. 30.

FIG. 32 is a schematic illustration of an inflatable balloon positionedwithin the occlusion device of FIG. 30.

FIG. 33 is a schematic view of a pull string deployment embodiment ofthe occlusion device of FIG. 30.

FIGS. 34A and 34B are side elevational schematic representations ofpartial and complete barrier layers on the occlusion device of FIG. 30.

FIG. 35 is a side elevational schematic view of an alternate occlusiondevice in accordance with the present invention.

FIG. 36 is a schematic view of a bonding layer mesh for use in forming acomposite barrier membrane in accordance with the present invention.

FIG. 37 is an exploded cross sectional view of the components of acomposite barrier member in accordance with the present invention.

FIG. 38 is a cross sectional view through a composite barrier formedfrom the components illustrated in FIG. 37.

FIG. 39 is a top plan view of the composite barrier illustrated in FIG.38.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1-3 show an embodiment of an occluding device 10 having featuresof the invention where an occluding member 11 is secured to a retentionmember 12 that is arranged to fix the occluding member in a desiredposition within a body passageway or cavity. The occluding member 11generally has disc shape with an outer rim 13 around the perimeter of aframe structure 14 which supports a barrier 15. The outer rim 13 can becircular or polygonal, or any other shape that is suitable forconforming to the inside surface of a body cavity. A hub 16 can belocated near the center of the occluding member 11 which serves toconnect the retention member 12 to the occluding member, in addition toother functions. The outer rim 13 is typically made from a soft polymermaterial 17 which permits flexibility of the outer rim and facilitatessealing of the outer rim against the inside surface of a body cavity orpassageway. The barrier 15 can be a thin mesh or film of material whichserves to block the passage of material within an area surrounded by theouter rim 13. The barrier 15 can be secured to the outer rim 13 alongits entire perimeter 18 in order to achieve a complete seal therebetweenand can be molded into the outer rim 13 or bonded thereto by a suitablemethod such as gluing, welding, sewing or other suitable method.

The outer rim 13 is at least partially supported by the frame structure14 which connects the outer rim and the hub. The frame structure 14 canbe made from one or more elements of high strength material such asstainless steel or MP35N, or may preferably be made from shape memory orpseudoelastic alloys such as NiTi, or any of a variety of knownstructural biodegradable materials (e.g. polyglycolic acid, poly lacticacid, poly-L-lactic acid and derivatives or copolymers such as PLGA).Preferably, the frame structure 14 is made from a material which can beself-expanding from a constrained configuration so that the occludingdevice 10 can be delivered to the deployment site in a low profile anflexible configuration which facilitates percutaneous delivery.

Preferably a radial hoop 21 is contained within the soft polymermaterial 17 of the outer rim 13 and serves to maintain the annular shapeof the outer rim and facilitate radial expansion of the outer rim from aconstrained position or configuration. The radial hoop 21 may beisolated within the soft polymer material 17 of the outer rim 13, or maybe connected to at least some of the elements 22 of the frame structure14, in order to have stronger mechanical joint between the outer rim andthe frame structure. The radial hoop 21 is shown in a substantiallycircular configuration, but may also be polygonal or otherwise suitablyshared, and may have connections or joints spaced thereon to facilitatecontraction or folding of the device for non-invasive delivery.

In addition to connecting the retention member 12 and the occludingmember 11, the hub 16 may serve to house a rotational coupling 23 whichis connected to the proximal end 24 of a tissue penetrating shaft 25within the retention member. The rotational coupling 23 allows thetransfer of torque to the tissue penetrating shaft 25 which preferablyhas a helically shaped extension or distal extremity 26 which isconfigured to screw into tissue and be mechanically fixed thereto.Longitudinal movement of the tissue penetrating shaft 25 relative to theretention member 12 and hub 16 may be prevented by sizing a lumen 27 ofthe retention member which contains the tissue penetrating shaft suchthat the helically shaped extension 26 at the distal end is too large topass through the lumen and the proximal end 24 of the tissue penetratingshaft is prevented from passing through the lumen by the rotationalcoupling attached thereto. The rotational coupling 23 may also beconfigured to be longitudinally captured by the hub 16 but still berotatably disposed therein.

FIGS. 3A and 3B depict an alternative embodiment of an occluding device10 having an occluding member 11 and a retention member 12. Theretention member 12 has a shaft 28 and radially extending members 29extending radially from a proximal end of the shaft. The radiallyextending members 29 serve to anchor the shaft 28 and the occludingmember 11 by engaging the tissue surrounding the occluding device.Preferably, the radially extending members are self-expanding from aconstricted state and are made of a pseudo elastic alloy such as NiTi,or a high strength material such as stainless steel. Although it ispreferable for the radially extending members 29 to be self-expandingfrom a constricted state, they may also be expanded by use of shapememory properties or a radial outward force as would be provided by aninflatable balloon or the like. The shaft 28 can be a single element ormade of multiple elements, and can be made from the same materials asthe radially extending members or different materials such as polymersor polymer composites. The radially extending members 29 have aproximally directed bias at their radial extremities 29A so that themembers readily fold down and move easily in a distal direction duringinsertion of the occluding device 10, but spring outward andaggressively engage surrounding tissue upon movement in a proximaldirection. This configuration of the radially extending members 29allows easy insertion into a body cavity, but prevents egress of thedevice 10 in and outward or proximal direction.

FIG. 4 depicts an occluding device 30 similar to that depicted in FIGS.1-3 deployed within the left atrial appendage 31 of a patient. An outerrim or periphery 32 of the occluding device 30 is disposed adjacent theopening 33 of the left atrial appendage 31 in a position which allowsfor a substantial seal of the outer rim against the inside surface 34 ofthe LAA. A helically shaped distal extremity 35 of a tissue penetratingshaft 36 has been screwed into the wall tissue of the LAA and ismechanically secured thereto. A retention member 38 maintains theposition of an occluding member 41 in a substantially perpendicularorientation with respect to a longitudinal axis of the LAA 42.

FIG. 5 depicts an occluding device similar to that depicted in FIGS. 1-4deployed within a LAA 51 of a patient similar to what is shown in FIG.4. The structure of an occluding member 52 of the embodiment as shown inFIG. 5 differs from that shown in FIG. 4 in that a barrier 53 and framestructure 54 of the embodiment of FIG. 5 protrudes proximally from aplane defined by an outer rim 55. This configuration may be useful forcertain morphologies of patient's LAAs. One object of the invention isto create a smooth surface outside the body passageway or cavity inorder to prevent turbulent flow or eddies of blood or other bodily fluidwithin the cavity or passageway. The alternative configuration of theoccluding device 50 shown in FIG. 5 may be useful in this regard.

FIG. 6 shows an alternative embodiment of an occluding device 60 whichhas an occluding member 61, a frame structure 62, a barrier 63 and aretention member in the form of an expandable member 65 which has linkedelements 66 that are preferably expandable from a constrainedconfiguration. The expandable member 65 is generally cylindrical inshape and can have a series of circumferential linked elements 66connected by links 68. Although FIG. 6 depicts the expandable member 65as a series of linked elements 66, those skilled in the art will realizethat a similar effect can be achieved with a single wire in a helicalconfiguration or a plurality of wires in a mesh or braidedconfiguration, or any other suitable configuration that can beself-expanding from a constrained configuration or expanding with theapplication of heat or other form of energy or force. For example, theexpandable member 65 may be configured to be deployed by an outwardradial force delivered from within the expandable member. An inflatableballoon or the like could be used to exert such a force. The expandablemember is preferably secured to an outer rim 71 of the occluding member61 but may also be secured to the frame structure 62 directly orindirectly. The expandable member 65 can be self-expanding from aconstrained configuration as can the occluding member 61 and the framestructure 62 and outer rim 71 thereof. The frame structure 62, outer rim71 and barrier 63 may have construction similar to that described abovewith regard to the similar elements of the embodiments depicted in FIGS.1-5.

Referring to FIG. 7, the expandable member 65 as shown in FIG. 6 mayalso have a sheath 72 disposed around it so as to act as a shieldbetween the expandable member and an inner surface of a patient's bodycavity or passageway. The sheath 72 may facilitate the sealing functionof the occluding member 61, but is primarily intended to prevent damageto either tissue on the inside surface of a body cavity or to the linkedelements 66 of the expandable member. The sheath 72 may surround all orpart of the expandable member 65 and may be made from a variety ofsuitable biocompatible materials such as Dacron.™., Nylon, TFE, PTFE orePTFE. The sheath 72 may be a weave, braid, film or have any othersuitable configuration. Expandable member 65 may also be coated bydipping, spraying, or other suitable process with a friction reducingmaterial such as Teflon.™., or with an active compound such as heparin.

FIG. 8 shows a transverse cross-sectional view of the embodiment of FIG.7 taken at lines 8-8. The frame structure 62 has an axis or hub 73disposed at approximately the center of the frame structure which servesto connect the various radial elements 74 of the frame structure. Thehub 73 can have an independent structure that links the several elements74 of the frame structure 62 or it may be merely the terminus of thevarious frame structure elements and have a solid composition. In eitherstructure, the hub 73 preferably allows a constrained configuration ofthe occluding member 61 to facilitate percutaneous delivery of theoccluding device 60. The hub 73 may also have a lumen disposed thereinto allow passage of a guidewire of other guiding member. Preferably, thelumen would have a self sealing valve or gasket which prevents thepassage of fluid or embolic material once the guidewire or guidingmember is removed from the lumen.

Referring to FIG. 9, a schematic view of a patient's heart 80 in partialsection shows a trans-septal catheter 81 having a proximal end 82 and adistal end 83. The distal end 83 of the trans-septal catheter 81 isdisposed within a patient's heart 80 with the distal end 84 of adelivery catheter 85 extending from the distal end 83 of thetrans-septal catheter. The distal end 83 of the trans-septal catheter 81has breached the septum 86 of the patient's heart 80 and is disposedadjacent the opening of the patient's LAA 88. At the proximal end 82 ofthe trans-septal catheter 81 there is a Luer connector 91 coupled to ahemostasis valve 92 which prevents the egress of blood from a lumen 93of the trans-septal catheter 81. The proximal end 94 of the deliverycatheter 85 extends proximally from the hemostasis valve 92 and has aLuer connector 95 attached to the proximal extremity thereof. Theproximal end 96 of a plunger 97 extends from the Luer connector 95 ofthe delivery catheter. The proximal end 94 of the delivery catheter isarranged to allow rotational and axial movement of the plunger 97 whilepreventing blood or other bodily fluids from leaking between thedelivery catheter 85 and the plunger 97.

Referring to FIG. 10, a patient's heart 80 is shown in partial sectionwith the distal end 84 of a delivery catheter 85 disposed within the LAAopening 87. FIG. 11 is a magnified view of the LAA 88 shown in FIG. 10and the distal end of the delivery catheter 84, which is shown inpartial section, contains a plunger 97 which is slideably disposedwithin an inner lumen 98 of the delivery catheter 85 and serves to applyaxial force in a distal direction on the collapsed occluding member 101disposed within the delivery catheter so as to force the occludingdevice 102 from the delivery catheter and deploy it. An occluding device102 having an expandable member 103 and an occluding member 101 securedthereto is partially deployed and extending from the distal end of thedelivery catheter 84 into the patient's LAA 88. The occluding device 102can also be guided into the patient's LAA 88 by use of an appropriateguidewire or guiding member.

FIG. 12 shows the occluding device 102 of FIG. 11 in a deployed statewithin the patient's LAA 88. An outer rim 104 of the occluding member101 is in substantial sealing contact with the inside surface 105 of theLAA 88. The expandable member 103 has expanded so as to contact theinside surface 105 of the LAA and secure the occluding device 102thereto and maintain the occluding member 101 in a substantiallyperpendicular orientation relative to a longitudinal axis 106 of the LAA88. A barrier 107 is disposed within an area bounded by the outer rim104 and is positioned to prevent the passage or embolic or othermaterial to or from the LAA 88. The distal end 108 of the plunger 97 isextending from the distal end of the delivery catheter 84 after havingpushed the occluding device 102 from the delivery catheter.

Referring to FIG. 13, an occluding device 110 having features of theinvention is shown. The occluding device 110 has a delivery catheter 111with a distal end 112, a detachment mechanism 113 disposed on the distalend of the delivery catheter and an occlusive body or inflatable member114 detachably secured to the detachment mechanism. The inflatablemember 114 has a proximal end 115 and a distal end 116 with the proximalend being attached to the detachment mechanism 113 and the distal endterminating at an end cap 117. The inflatable member 114 has an outsidesurface 118 that may contain a fibrosis inducing material such asDacron.™. or other similar materials. The inflatable member 114 may bemade from a fluid tight film of polymer material which can be eithercompliant or non-compliant. Preferably the inflatable member 114 is madefrom silicone, however, any suitable material such as polyethylene,polyurethane or PET can be used.

The detachment mechanism 113 can be activated by mechanical force or bydelivery of thermal or optical energy by a suitable conduit.Alternatively, the inflatable member can be pushed into the LAA from thedelivery catheter 111 by an elongate push member without the use of adetachment mechanism. The inflatable member 114 can be filled with agas, fluid or gel which is injected under pressure through the deliverycatheter 114 and into the inflatable member. Suitable fluids to injectwould include saline and silicone. The inflatable member 114 may also befilled with a polymer material that can be hardened. Autologus fluidsuch as blood, or collagen may also be used. A fluid, gel or polymerused to fill the inflatable member may contain contrast agents such asgold, tantalum, bismuth, barium sulfate or the like in order to improvevisualization under fluoroscopy or x-ray imaging.

FIG. 14 is a transverse cross-sectional view of the occluding device 110of FIG. 13 taken along lines 14-14. An optional inner shaft 121 is showndisposed within the inflatable member 114, preferably in a concentricarrangement. The inner shaft 121 provides longitudinal axial support tothe inflatable member 114 so as to maintain a longitudinal dimension ofthe inflatable member 114 when it is being inflated and deployed. Theinner shaft 121 may be solid or contain one or more lumens that may ormay not be in fluid communication with an inner lumen 122 of theinflatable member 114, and can be used for the passage of a guidewire orguiding member.

FIG. 15 depicts an alternative embodiment of an occluding device 110which consists of an inflatable member 114 similar to the inflatablemember of FIG. 13, shown substantially deployed, within a patient's LAA123. The inflatable member 114 has been at least partially filled with afluid, gas or gel, within the patient's LAA 123 such that the outsidesurface of the inflatable member 118 is in contact with at least part ofthe inside surface 124 of the LAA. The inflatable member 114 can haverib members 125 which can mechanically interlock with the trebeculae 126of the inside surface of the LAA 124 or other surface irregularities ofthe inside surface of a patient's body cavity or passageway. The ribmembers 125 form a complete circumference of the inflatable member 114,but could also form a partial circumference, spiral configuration, orconsist of random projections on the surface of the inflatable member118. The rib members 125 should extend radially about 1 to about 4 mmfrom the nominal surface of the inflatable member 114, and arepreferably spaced about 3 to about 8 mm from each other. The rib members125 may be made from any suitable polymer material, but are preferablymade from the same material as the inflatable member, and are integrallymolded thereon, or bonded thereto with a heat weld or adhesive bondsuitable for bonding flexibly medical polymers. The inflatable member114 is depicted with the distal end of the delivery catheter 112 anddetachment mechanism 113 attached. As an alternative, or in addition tothe polymer rib members 125 shown in FIG. 15, barbs or hooks could besecured to the outside surface of the inflatable member 114 which areconfigured to engage the inside surface of a patient's LAA 124.Preferably, barbs or hooks disposed on the outside surface of theinflatable member and configured to engage the tissue of the insidesurface of a patient's LAA 124 would have a proximally directed bias attheir radial extremity so that the barbs would fold down and move easilyin a distal direction during insertion of the inflatable member 114, butwould spring outward and aggressively engage the tissue of the bodycavity upon movement in a proximal direction of the inflatable member.

FIG. 16 depicts an occluding device 110 consisting of an inflatablemember 114 which is shown deployed within a patient's LAA 123. Theembodiment of the inflatable member 114 shown in FIG. 16 has an optionalretention member 127 with a tissue penetrating shaft 128 which has aproximal 131 end and a distal end 132. A rotational coupling 133 isdisposed at the proximal end 131 of the tissue penetrating shaft 128 anda helically shaped extremity 134 is disposed at the distal end of theshaft 132. The helically shaped distal extremity 134 is shown deployedwithin and mechanically engaging wall tissue 135 of the LAA so as tosecure the inflatable member 114 and maintain its position within theLAA 123 of the patient.

FIG. 17 shows an alternative embodiment of an occlusive member 140consisting of a polymer mass 141 which has been injected or deliveredinto a patient's LAA 142. The distal end 143 of a delivery catheter 144has a lumen 145 therein which extends to a proximal end of the deliverycatheter which is in fluid communication with a source of pressurizedpolymer material. A source of pressurized polymer material 146 can beany type of pump or device capable of forcing a polymer fluid or gelinto the proximal end of the delivery catheter with sufficient pressureto force the polymer fluid or gel out the distal end 143 of the deliverycatheter 144 and into a patient's body cavity or passageway.

The delivery catheter 144 may be positioned by the techniques discussedabove, e.g., the Mullins trans-septal approach or any other suitablemethod. Once the distal end of the delivery catheter 143 is disposedwithin a desired portion of the patient's LAA 142, the polymer mass 141may be injected to fill the cavity to the desired level. The LAA 142 canbe completely or partially filled with the polymer mass 141 which can beformulated to harden over time, with heat or remain in a fluid or gelstate. The distal end of the delivery catheter can optionally include anexpandable member which is used to substantially seal the deliverycatheter against the inside surface of the opening of the patient's bodycavity during the delivery of polymer material. The expandable membercan be an inflatable balloon or the like which are well known in theart.

Optionally, a retention member 127 having a tissue penetrating shaft 128or the like, such as shown in FIG. 16 with regard to the inflatablemember 114, may be deployed within the LAA 142 prior to injection of thepolymer mass 141 and captured thereby so as to secure the polymer masswithin the LAA. Alternatively, the polymer mass can be used to fill thepatient's LAA and surround and secure a deployed device as shown in FIG.4 or 5 in the patient's LAA 142.

Once a desired amount of polymer mass 141 has been injected into the LAA142, as assessed for example by TE Echo imaging, the delivery catheter144 may be withdrawn and the procedure terminated. Preferably, theentire LAA 142 of a patient is filled with the polymer mass 141 as shownin FIG. 18 and hardens or gels to maintain its shape. It may bedesirable to have the polymer mass 141 retain a soft compressible formafter setting or hardening so that it is at least partially compliantwith the constrictive pumping action of a heart and resistant to fatigueas a result thereof. A material used to form the polymer mass 141 maycontain contrast agents such as gold, platinum, tantalum, bismuth or thelike in order to better visualize the deployment of the polymer massunder fluoroscopic or x-ray imaging.

Another alternative embodiment of an occlusive member 140 can be foundin FIG. 19 which shows an occlusive coil 147 which has been deployedwithin an LAA 142. The occlusive coil 147 as shown has assumed a randomconfiguration that is mechanically occluding the LAA 142 and which hasinduced clot and/or fibrosis formation 148 which further facilitatesocclusion of the LAA 142.

An apparatus for closing off a body cavity or passageway 150 is shown inFIG. 20 which has features of the present invention. The apparatus 150has an elongate shaft 151 with an inner lumen 152 and a proximal end 153and a distal end 154. Slideably disposed within the inner lumen 152 ofthe elongate shaft 151 are at least two elongate members 155 which haveproximal ends 156 and distal ends 157 and have tissue attachment members158 disposed on the distal ends. An optional distal anchor member 161 isalso slideably disposed within the inner lumen 152 of the elongate shaft151 and preferably has a distal end 162 terminating with a helicalmember 163. The proximal end 153 of the elongate shaft 151 has aproximal control module 164 which seals the inner lumen 152 of theelongate shaft 151 and allows rotation and translation of the proximalends 156 of the elongate members 155 and the distal anchor member 161while maintaining a seal between said members to prevent leakage ofbodily fluids therefrom. The proximal control module 164 can optionallybe configured to control advancement and retraction of the elongatemembers 155 and control activation of the tissue attachment members 158.

FIG. 21 shows the apparatus for closing off a body cavity 150 of FIG. 20with the distal ends of the elongate members 157 and the tissueattachment members 158 extending distally from the distal end of theelongate shaft 154. The distal ends of the elongate members 157 areangled or deflected from a longitudinal axis 165 of the elongate shaft151 so as to engage tissue 166 of the opening 167 of the LAA 168 asshown. The elongate members 155 may be deflected by an abutment orangulation contained in the distal end of the elongate shaft 154, butare preferably preshaped in an angled configuration which manifests whenthe distal ends are freed of the constraint of the inner lumen 152 ofthe elongate shaft an allowed to assume their relaxed preshapedcondition. The helical member 163 at the distal end 162 of the distalanchor member 161 is engaged with the wall tissue 171 of the LAA 168 soas to provide an optional anchor that can be used to move the elongateshaft 151 relative to the distal anchor member 161 and give greatercontrol of the longitudinal axial movement of the elongate shaftrelative to the LAA opening 167. The tissue attachment members 158 areshown attached to the annular edge 172 of the LAA opening 167. Once thetissue attachment members 158 are attached, a closure member orretaining ring 173 may be advanced distally by applying axial force onan elongate push shaft 174 which draws the tissue attachment members 158and the tissue attached thereto closer together as shown in FIG. 22. Asthe closure member 173 is further advanced distally, the annular edge ofthe LAA 172 is drawn closed, and eventually, the annular edge of the LAAwill be completely closed into a closed state with the closure member173 surrounding and compressing the tissue of the annular edge as shownin FIG. 23. Once a closed state of the LAA is achieved, the tissueattachment members 158 may be detached, and the apparatus for closingoff a body cavity 150 withdrawn. One alternative method can have thetissue attachment members 158 drawn together by retracting themproximally into the distal end 154 of the elongate shaft 151 as opposedto distally advancing the closure member 173 with the elongate pushshaft 174. In this way, the annular edge of the LAA 172 can be drawninto a closed state within the distal end 154 of the elongate shaft 151at which point the annular edge may be fixed in the closed state by avariety of methods including suturing, tissue welding, the applicationof a suitable biocompatible adhesive, surgical staples or the like.

Referring to FIGS. 24 and 25, there is illustrated an alternateembodiment of the occlusion device 10 in accordance with the presentinvention. The occlusion device 10 comprises an occluding member 11comprising a frame 14 and a barrier 15. In the illustrated embodiment,the frame 14 comprises a plurality of radially outwardly extendingspokes 17 each having a length within the range of from about 0.5 cm toabout 2 cm from a hub 16. In one embodiment, the spokes have an axiallength of about 1.5 cm. Depending upon the desired introduction crossingprofile of the collapsed occlusion device 10, as well as structuralstrength requirements in the deployed device, anywhere within the rangeof from about 3 spokes to about 40 spokes may be utilized. In someembodiments, anywhere from about 12 to about 24 spokes are utilized,and, 18 spokes are utilized in one embodiment.

The spokes are advanceable from a generally axially extendingorientation such as to fit within a tubular introduction catheter to aradially inclined orientation as illustrated in FIG. 24 and FIG. 25following deployment from the catheter. In a self-expandable embodiment,the spokes are biased radially outwardly such that the occlusion memberexpands to its enlarged, implantation cross-section under its own biasfollowing deployment from the catheter. Alternatively, the occlusionmember may be enlarged using any of a variety of enlargement structuressuch as an inflatable balloon.

Preferably, the spokes comprise a metal such as stainless steel,Nitinol, Elgiloy, or others which can be determined through routineexperimentation by those of skill in the art. Wires having a circular orrectangular cross-section may be utilized depending upon themanufacturing technique. In one embodiment, rectangular cross sectionspokes are cut such as by known laser cutting techniques from tubestock, a portion of which forms the hub 16.

The barrier 15 may comprise any of a variety of materials whichfacilitate cellular in-growth, such as ePTFE. The suitability ofalternate materials for barrier 15 can be determined through routineexperimentation by those of skill in the art. The barrier 15 may beprovided on either one or both sides of the occlusion member. In oneembodiment, the barrier 15 comprises two layers, with one layer on eachside of the frame 14. The two layers may be bonded to each other aroundthe spokes 17 in any of a variety of ways, such as by heat bonding withor without an intermediate bonding layer such as polyethylene or FEP,adhesives, sutures, and other techniques which will be apparent to thoseof skill in the art in view of the disclosure herein. The barrier 15preferably has a thickness of no more than about 0.003″ and a porositywithin the range of from about 5 .mu.m to about 60 .mu.m.

The barrier 15 in one embodiment preferably is securely attached to theframe 14 and retains a sufficient porosity to facilitate cellularingrowth and/or attachment. One method of manufacturing a suitablecomposite membrane barrier 15 is illustrated in FIGS. 36-39. Asillustrated schematically in FIG. 36, a bonding layer 254 preferablycomprises a mesh or other porous structure having an open surface areawithin the range of from about 10% to about 90%. Preferably, the opensurface area of the mesh is within the range of from about 30% to about60%. The opening or pore size of the bonding layer 254 is preferablywithin the range of from about 0.005 inches to about 0.050 inches, and,in one embodiment, is about 0.020 inches. The thickness of the bondinglayer 254 can be varied widely, and is generally within the range offrom about 0.0005 inches to about 0.005 inches. In a preferredembodiment, the bonding layer 254 has a thickness of about 0.001 toabout 0.002 inches. One suitable polyethylene bonding mesh is availablefrom Smith and Nephew, under the code SN9.

Referring to FIG. 37, the bonding layer 254 is preferably placedadjacent one or both sides of a spoke or other frame element 14. Thebonding layer 254 and frame 14 layers are then positioned in-between afirst membrane 250 and a second membrane 252 to provide a compositemembrane stack. The first membrane 250 and second 252 may comprise anyof a variety of materials and thicknesses, depending upon the desiredfunctional result. Generally, the membrane has a thickness within therange of from about 0.0005 inches to about 0.010 inches. In oneembodiment, the membranes 250 and 252 each have a thickness on the orderof from about 0.001 inches to about 0.002 inches, and comprise porousePTFE, having a porosity within the range of from about 10 microns toabout 100 microns.

The composite stack is heated to a temperature of from about 200.degree.to about 300.degree., for about 1 minute to about 5 minutes underpressure to provide a finished composite membrane assembly with anembedded frame 14 as illustrated schematically in FIG. 38. The finalcomposite membrane has a thickness within the range of from about 0.001inches to about 0.010 inches, and, preferably, is about 0.002 to about0.003 inches in thickness. However, the thicknesses and processparameters of the foregoing may be varied considerably, depending uponthe materials of the bonding layer 254 the first layer 250 and thesecond layer 252.

As illustrated in top plan view in FIG. 39, the resulting finishedcomposite membrane has a plurality of “unbonded” windows or areas 256suitable for cellular attachment and/or ingrowth. The attachment areas256 are bounded by the frame 14 struts, and the cross-hatch patternformed by the bonding layer 254. In the illustrated embodiment, thefilaments of the bonding layer 254 are oriented in a nonparallelrelationship with the struts of frame 14, and, in particular, at anangle within the range of from about 15.degree. to about 85.degree. fromthe longitudinal axis of the struts. Preferably, a regular window 256pattern is produced.

The foregoing procedure allows the bonding mesh to flow into the firstand second membranes 250 and 252 and gives the composite membrane 15greater strength (both tensile and tear strength) than the componentswithout the bonding mesh. The composite allows uniform bonding whilemaintaining porosity of the membrane 15, to facilitate tissueattachment. By flowing the thermoplastic bonding layer into the pores ofthe outer mesh layers 250 and 252, the composite flexibility ispreserved and the overall composite layer thickness can be minimized.

The occlusion device 10 may be further provided with a bulking elementor stabilizer 194. The stabilizer 194 may be spaced apart along an axisfrom the occluding member 11. In the illustrated embodiment, a distalend 190 and a proximal end 192 are identified for reference. Thedesignation proximal or distal is not intended to indicate anyparticular anatomical orientation or deployment orientation within thedeployment catheter. As shown in FIGS. 24 and 25, the stabilizer 194 isspaced distally apart from the occluding member 11.

For use in the LAA, the occluding member 11 has an expanded diameterwithin the range of from about 1 cm to about 5 cm, and, in oneembodiment, about 3 cm. The axial length of the occluding member 11 inan expanded, unstressed orientation from the distal end 192 to theproximal hub 16 is on the order of about 1 cm. The overall length of theocclusion device 10 from the distal end 192 to the proximal end 190 iswithin the range of from about 1.5 cm to about 4 cm and, in oneembodiment, about 2.5 cm. The axial length of the stabilizer 194 betweendistal hub 191 and proximal hub 16 is within the range of from about 0.5cm to about 2 cm, and, in one embodiment, about 1 cm. The expandeddiameter of the stabilizer 194 is within the range of from about 0.5 cmto about 2.5 cm, and, in one embodiment, about 1.4 cm. The outsidediameter of the distal hub 191 and proximal hub 16 is about 2.5 mm.

Preferably, the occlusion device 10 is provided with one or moreretention structures for retaining the device in the left atrialappendage or other body lumen. In the illustrated embodiment, aplurality of barbs or other anchors 195 are provided, for engagingadjacent tissue to retain the occlusion device 10 in its implantedposition and to limit relative movement between the tissue and theocclusion device. The illustrated anchors are provided on one or more ofthe spokes 17, or other portion of frame 14. Preferably, every spoke,every second spoke or every third spoke are provided with one or twoanchors each. The illustrated anchor is in the form of a barb, forextending into tissue at or near the opening of the LAA.

One or more anchors 195 may also be provided on the stabilizer 194, suchthat it assists not only in orienting the occlusion device 10 andresisting compression of the LAA, but also in retaining the occlusiondevice 10 within the LAA. Any of a wide variety of structures may beutilized for anchor 195, either on the occluding member 11 or thestabilizer 194 or both, such as hooks, barbs, pins, sutures, adhesivesand others which will be apparent to those of skill in the art in viewof the disclosure herein.

In use, the occlusion device 10 is preferably positioned within atubular anatomical structure to be occluded such as the left atrialappendage such that the occluding member 11 is positioned across or nearthe opening to the LAA and the stabilizer 194 is positioned within theLAA. The stabilizer 194 assists in the proper location and orientationof the occluding member 11, as well as resists compression of the LAAbehind the occluding member 11. The present inventors have determinedthat following deployment of an occluding member 11 without a stabilizer194 or other bulking structure to resist compression of the LAA, normaloperation of the heart may cause compression and resulting volumechanges in the LAA, thereby forcing fluid past the occluding member 11and inhibiting or preventing a complete seal. Provision of a stabilizer194 dimensioned to prevent the collapse or pumping of the LAA thusminimize leakage, and provision of the barbs facilitatesendothelialization or other cell growth across the occluding member 11.

For this purpose, the stabilizer 194 is preferably movable between areduced cross-sectional profile for transluminal advancement into theleft atrial appendage, and an enlarged cross-sectional orientation asillustrated to fill or to substantially fill a cross-section through theLAA. The stabilizing member may enlarge to a greater cross section thanthe anatomical cavity, to ensure a tight fit and minimize the likelihoodof compression. One convenient construction includes a plurality ofelements 196 which are radially outwardly expandable in response toaxial compression of a distal hub 191 towards a proximal hub 16.Elements 196 each comprise a distal segment 198 and a proximal segment202 connected by a bend 200. The elements 196 may be provided with abias in the direction of the radially enlarged orientation asillustrated in FIG. 25, or may be radially expanded by applying anexpansion force such as an axially compressive force between distal hub191 and proximal hub 16 or a radial expansion force such as might beapplied by an inflatable balloon: Elements 196 may conveniently beformed by laser cutting the same tube stock as utilized to construct thedistal hub 191, proximal hub 16 and frame 14, as will be apparent tothose of skill in the art in view of the disclosure herein.Alternatively, the various components of the occlusion device 10 may beseparately fabricated or fabricated in subassemblies and securedtogether during manufacturing.

As a post implantation step for any of the occlusion devices disclosedherein, a radiopaque dye or other visualizable media may be introducedon one side or the other of the occlusion device, to permitvisualization of any escaped blood or other fluid past the occlusiondevice. For example, in the context of a left atrial appendageapplication, the occlusion device may be provided with a capillary tubeor aperture which permit introduction of a visualizable dye from thedeployment catheter through the occlusion device and into the entrappedspace on the distal side of the occlusion device. Alternatively, dye maybe introduced into the entrapped space distal to the occlusion devicesuch as by advancing a small gauge needle from the deployment catheterthrough the barrier 15 on the occlusion device, to introduce dye.

A further embodiment of the occlusion device 10 is illustrated in FIGS.26-27. The occlusion device 10 comprises an occlusion member 11 and astabilizing member 194 as in the previous embodiment. In the presentembodiment, however, each of the distal segments 198 inclines radiallyoutwardly in the proximal direction and terminates in a proximal end204. The proximal end 204 may be provided with atraumatic configuration,for pressing against, but not penetrating, the wall of the left atrialappendage or other tubular body structure. Three or more distal segments198 are preferably provided, and generally anywhere within the range offrom about 6 to about 20 distal segments 198 may be used. In oneembodiment, 9 distal segments 198 are provided. In this embodiment, 3 ofthe distal segments 198 have an axial length of about 5 mm, and 6 of thedistal segments 198 have an axial length of about 1 cm. Staggering thelengths of the proximal segments 198 may axially elongate the zone inthe left atrial appendage against which the proximal ends 204 provideanchoring support for the occlusion device.

The occlusion device 10 illustrated in FIGS. 26 and 27 is additionallyprovided with a hinge 206 to allow the longitudinal axis of theocclusion member 11 to be angularly oriented with respect to thelongitudinal axis of the stabilizing member 194. In the illustratedembodiment, the hinge 206 is a helical coil, although any of a varietyof hinge structures can be utilized. The illustrated embodiment may beconveniently formed by laser cutting a helical slot through a section ofthe tube from which the principal structural components of the occlusiondevice 10 are formed. At the distal end of the hinge 206, an annularband 208 connects the hinge 206 to a plurality of axially extendingstruts 210. In the illustrated embodiment 210, three axial struts 210are provided, spaced equilaterally around the circumference of the body.Axial struts 210 may be formed from a portion of the wall of theoriginal tube stock, which portion is left in its original axialorientation following formation of the distal segments 198 such as bylaser cutting from the tubular wall.

The occlusion member 11 is provided with a proximal zone 212 on each ofthe spokes 17. Proximal zone 212 has an enhanced degree of flexibility,to accommodate the fit between the occlusion member 11 and the wall ofthe left atrial appendage. Proximal section 212 may be formed byreducing the cross sectional area of each of the spokes 17, or byincreasing the length of each spoke by making a wave pattern asillustrated.

Each of the spokes 17 terminates in a proximal point 214. Proximal point214 may be contained within layers of the barrier 15, or may extendthrough or beyond the barrier 15 such as to engage adjacent tissue andassist in retaining the occlusion device 10 at the deployment site.

Referring to FIGS. 28 and 29, a further variation on the occlusiondevice 10 illustrated in FIGS. 24 and 25 is provided. The occlusiondevice 10 is provided with a proximal face 216 on the occlusion member11, instead of the open and proximally concave face on the embodiment ofFIGS. 24 and 25. The proximal face 216 is formed by providing a proximalspoke 218 which connects at an apex 220 to each distal spoke 17.Proximal spokes 218 are each attached to a hub 222 at the proximal end192 of the occlusion device 10. The barrier 15 may surround either theproximal face or the distal face or both on the occlusion member 11. Ingeneral, provision of a proximal spoke 218 connected by an apex 220 to adistal spoke 17 provides a greater radial force than a distal spoke 17alone, which will provide an increased resistance to compression if theocclusion member 11 is positioned with the LAA.

Referring to FIGS. 30-35, an alternate embodiment of the occlusiondevice in accordance with the present invention is illustrated. Ingeneral, the occlusion device 10 comprises an occluding member but doesnot include a distinct stabilizing member as has been illustrated inconnection with previous embodiments. Any of the embodiments previouslydisclosed herein may also be constructed using the occluding memberonly, and omitting the stabilizing member as will be apparent to thoseof skill in the art in view of the disclosure herein.

The occluding device 10 comprises a proximal end 192, a distal end 190,and a longitudinal axis extending therebetween. A plurality of supports228 extend between a proximal hub 222 and a distal hub 191. At least twoor three supports 228 are provided, and preferably at least about six.In one embodiment, eight supports 228 are provided. However, the precisenumber of supports 228 can be modified, depending upon the desiredphysical properties of the occlusion device 10 as will be apparent tothose of skill in the art in view of the disclosure herein, withoutdeparting from the present invention.

Each support 228 comprises a proximal spoke portion 218, a distal spokeportion 217, and an apex 220 as has been discussed. However, each of theproximal spoke 218, distal spoke 17 and apex 220 may be a region on anintegral support 228, such as a continuous rib or frame member whichextends in a generally curved configuration as illustrated with aconcavity facing towards the longitudinal axis of the occlusion device10. Thus, no distinct point or hinge at apex 220 is necessarily providedas is disclosed in previous embodiments, which include a hingedconnection between proximal spoke 218 and distal spoke 17.

At least some of the supports 228, and, preferably, each support 228, isprovided with one or two or more barbs 195. In the illustratedconfiguration, the occlusion device 10 is in its enlarged orientation,such as for occluding a left atrial appendage or other body cavity orlumen. In this orientation, each of the barbs 195 projects generallyradially outwardly from the longitudinal axis, and are inclined in theproximal direction. In an embodiment where the barbs 195 andcorresponding support 228 are cut from a single ribbon, sheet or tubestock, the barb 195 will incline radially outwardly at approximately atangent to the curve formed by the support 228.

The occlusion device 10 illustrated in FIG. 30 may be constructed in anyof a variety of ways, as will become apparent to those of skill in theart in view of the disclosure herein. In one preferred method, theocclusion device 10 is constructed by laser cutting a piece of tubestock to provide a plurality of axially extending slots in-betweenadjacent supports 228. Similarly, each barb 195 can be laser cut fromthe corresponding support 228 or space in-between adjacent supports 228.The generally axially extending slots which separate adjacent supports228 end a sufficient distance from each of the proximal end 192 anddistal end 190 to leave a proximal hub 222 and a distal hub 191 to whicheach of the supports 228 will attach. In this manner, an integral cagestructure may be formed. Alternatively, each of the components of thecage structure may be separately formed and attached together such asthrough soldering, heat bonding, adhesives, and other fasteningtechniques which are known in the art. A further method of manufacturingthe occlusion device 10 is to laser cut a slot pattern on a flat sheetof appropriate material, such as a flexible metal or polymer, as hasbeen discussed in connection with previous embodiments. The flat sheetmay thereafter be rolled about an axis and opposing edges bondedtogether to form a tubular structure.

The apex portion 220 which carries the barb 195 may be advanced from alow profile orientation in which each of the supports 228 extendgenerally parallel to the longitudinal axis, to an implanted orientationas illustrated, in which the apex 220 and the barb 195 are positionedradially outwardly from the longitudinal axis. The support 228 may bebiased towards the enlarged orientation, or may be advanced to theenlarged orientation following positioning within the tubular anatomicalstructure, in any of a variety of manners. For example, referring toFIG. 32, an inflatable balloon 230 is positioned within the occlusiondevice 10. Inflatable balloon 230 is connected by way of a removablecoupling 232 to an inflation catheter 234. Inflation catheter 234 isprovided with an inflation lumen for providing communication between aninflation media source 236 outside of the patient and the balloon 230.Following positioning within the target body lumen, the balloon 230 isinflated, thereby engaging barbs 195 with the surrounding tissue. Theinflation catheter 234 is thereafter removed, by decoupling theremovable coupling 232, and the inflation catheter 234 is thereafterremoved.

In an alternate embodiment, the supports 228 are radially enlarged suchas through the use of a deployment catheter 238. Deployment catheter 238comprises a lumen for movably receiving a deployment line 240.Deployment line 240 extends in a loop 244 formed by a slip knot 242. Aswill be apparent from FIG. 33, proximal retraction on the deploymentline 240 will cause the distal hub 191 to be drawn towards the proximalhub 222, thereby radially enlarging the cross-sectional area of theocclusion device 10. Depending upon the material utilized for theocclusion device 10, the supports 228 will retain the radially enlargedorientation by elastic deformation, or may be retained in the enlargedorientation such as by securing the slip knot 242 immovably to thedeployment line 240 at the fully radially enlarged orientation. This maybe accomplished in any of a variety of ways, using additional knots,clips, adhesives, or other techniques known in the art.

Referring to FIGS. 34A and 34B, the occlusion device 10 may be providedwith a barrier 15 such as a mesh or fabric as has been previouslydiscussed. Barrier 15 may be provided on only one hemisphere such asproximal face 216, or may be carried by the entire occlusion device 10from proximal end 192 to distal end 190. The barrier may be secured tothe radially inwardly facing surface of the supports 228, as illustratedin FIG. 34B, or may be provided on the radially outwardly facingsurfaces of supports 228, or both.

A further embodiment of the occlusion device 10 is illustrated in FIG.35, in which the apex 220 is elongated in an axial direction to provideadditional contact area between the occlusion device 10 and the wall ofthe tubular structure. In this embodiment, one or two or three or moreanchors 195 may be provided on each support 228, depending upon thedesired clinical performance. The occlusion device 10 illustrated inFIG. 35 may also be provided with any of a variety of other featuresdiscussed herein, such as a partial or complete barrier 15 covering. Inaddition, the occlusion device 10 illustrated in FIG. 35 may be enlargedusing any of the techniques disclosed elsewhere herein.

While particular forms of the invention have been described, it will beapparent that various modifications can be made without departing fromthe spirit and scope of the invention. Accordingly, it is not intendedthat the invention be limited, except as by the appended claims.

1. A method of preventing atrial appendage thrombus from entering theblood stream comprising: securing a membrane over an ostium of theatrial appendage by extending prongs from adjacent an edge of themembrane into the atrial appendage through the ostium; and piercing thewall of the atrial appendage with the prongs extending into the atrialappendage wall substantially adjacent the ostium to secure the membranein place; thereby: blocking the atrial appendage ostium with themembrane preventing blood from entering the atrial appendage and formingthrombus therein and preventing thrombus formed therein from leaving.